An organic electronic device means a device requiring exchanging of electric charges between an electrode using holes and/or electrons and an organic material. The organic electronic device may be largely divided into the following two types according to an operation principle. A first type is an electric device in which an exciton is formed in an organic material layer by a photon flowing from an external light source to the device, the exciton is separated into an electron and a hole, and the electron and the hole are transferred to the different electrodes to be used as a current source (voltage source). A second type is an electronic device in which holes and/or electrons are injected into an organic material semiconductor forming an interface together with the electrode by applying a voltage or a current to two or more electrodes, and the electronic device is operated by the injected electrons and holes.
Examples of the organic electronic device include an organic light emitting device, an organic solar cell, an organic photoconductor (OPC), an organic transistor, and the like, and all of the examples require a hole injection or transport material, an electron injection or transport material, or a light emitting material in order to drive the device. Hereinafter, an organic light emitting device will be mainly described in detail, but in the organic electronic devices, the hole injection or transport material, the electron injection or transport material, or the light emitting material is operated based on the similar principle.
In general, an organic light emitting phenomenon means a phenomenon where electric energy is converted into light energy by using an organic material. The organic light emitting device using the organic light emitting phenomenon has a structure generally including an anode, a cathode, and an organic material layer interposed therebetween. Herein, in many cases, the organic material layer has a multilayered structure constituted by different materials in order to increase efficiency and stability of the organic light emitting device, and for example, the organic material layer may be formed of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. In the structure of the organic light emitting device, if a voltage is applied between two electrodes, the holes are injected from the anode to the organic material layer and the electrons are injected from the cathode to the organic material layer, and when the injected holes and electrons meet each other, an exciton is formed, and light is emitted when the exciton falls to a bottom state again. It is known that this organic light emitting device has properties such as self light emission, high brightness, high efficiency, a low driving voltage, a wide viewing angle, a high contrast, and a high speed response property.
In the organic light emitting device, the material used as the organic material layer may be classified into a light emitting material and an electric charge transport material, for example, a hole injection material, a hole transport material, an electron transport material, an electron injection material, and the like, according to a function thereof. Further, the light emitting material may be classified into blue, green, and red light emitting materials and yellow and orange light emitting materials required in order to implement better natural colors according to a light emitting color. Meanwhile, in the case where only one material is used as the light emitting material, since there are problems in that a maximum light emitting wavelength moves to a long wavelength or color purity is lowered due to interaction between molecules or efficiency of the device is reduced due to a reduced effect of light emission, host/dopant systems may be used as the light emitting material in order to increase the color purity and increase light emitting efficiency through transference of energy.
In order to sufficiently show the aforementioned excellent properties of the organic light emitting device, support of a material forming the organic material layer in the device, for example, the hole injection material, the hole transport material, the light emitting material, the electron transport material, the electron injection material, and the like with stable and efficient materials should be previously performed, but development of a stable and efficient material of an organic material layer for an organic light emitting device has not yet been sufficiently made. Therefore, there is a continuous demand for developing a novel material, and the necessity for developing the novel material is similarly applied to aforementioned other organic electronic devices.